"""
部署策略工具类 - 实现不同的部署策略
"""
import asyncio
import logging
from typing import Dict, Any, List
from abc import ABC, abstractmethod
from datetime import datetime

from app.models.release import Release, ReleaseStep, ReleaseStatus
from app.core.config import current_settings

logger = logging.getLogger(__name__)


class BaseDeploymentStrategy(ABC):
    """部署策略基类"""
    
    def __init__(self, release: Release, db):
        self.release = release
        self.db = db
    
    @abstractmethod
    async def deploy(self) -> Dict[str, Any]:
        """执行部署"""
        pass
    
    async def execute_step(self, step: ReleaseStep) -> bool:
        """执行单个步骤"""
        try:
            step.status = ReleaseStatus.IN_PROGRESS
            step.started_at = datetime.utcnow()
            self.db.commit()
            
            # 执行步骤命令
            if step.command:
                success = await self._execute_command(step.command, step.timeout)
            else:
                # 模拟执行
                await asyncio.sleep(2)
                success = True
            
            if success:
                step.status = ReleaseStatus.SUCCESS
                step.completed_at = datetime.utcnow()
            else:
                step.status = ReleaseStatus.FAILED
                step.error_message = "步骤执行失败"
            
            self.db.commit()
            return success
            
        except Exception as e:
            step.status = ReleaseStatus.FAILED
            step.error_message = str(e)
            self.db.commit()
            logger.error(f"步骤执行失败: {e}")
            return False
    
    async def _execute_command(self, command: str, timeout: int) -> bool:
        """执行命令"""
        try:
            process = await asyncio.create_subprocess_shell(
                command,
                stdout=asyncio.subprocess.PIPE,
                stderr=asyncio.subprocess.PIPE
            )
            
            stdout, stderr = await asyncio.wait_for(
                process.communicate(),
                timeout=timeout
            )
            
            return process.returncode == 0
            
        except asyncio.TimeoutError:
            logger.error(f"命令执行超时: {command}")
            return False
        except Exception as e:
            logger.error(f"命令执行失败: {e}")
            return False


class BlueGreenDeployment(BaseDeploymentStrategy):
    """蓝绿部署策略"""
    
    async def deploy(self) -> Dict[str, Any]:
        """执行蓝绿部署"""
        try:
            logger.info(f"开始蓝绿部署: {self.release.version}")
            
            # 获取部署步骤
            steps = self.db.query(ReleaseStep).filter(
                ReleaseStep.release_id == self.release.id
            ).order_by(ReleaseStep.step_order).all()
            
            for step in steps:
                success = await self.execute_step(step)
                if not success:
                    return {
                        "success": False,
                        "error": f"步骤 {step.step_name} 执行失败",
                        "step": step.step_name
                    }
            
            logger.info(f"蓝绿部署完成: {self.release.version}")
            return {"success": True, "strategy": "blue_green"}
            
        except Exception as e:
            logger.error(f"蓝绿部署失败: {e}")
            return {"success": False, "error": str(e)}


class CanaryDeployment(BaseDeploymentStrategy):
    """金丝雀发布策略"""
    
    async def deploy(self) -> Dict[str, Any]:
        """执行金丝雀发布"""
        try:
            logger.info(f"开始金丝雀发布: {self.release.version}")
            
            # 获取部署步骤
            steps = self.db.query(ReleaseStep).filter(
                ReleaseStep.release_id == self.release.id
            ).order_by(ReleaseStep.step_order).all()
            
            for step in steps:
                success = await self.execute_step(step)
                if not success:
                    return {
                        "success": False,
                        "error": f"步骤 {step.step_name} 执行失败",
                        "step": step.step_name
                    }
                
                # 金丝雀发布需要等待和验证
                if "健康检查" in step.step_name:
                    await asyncio.sleep(5)  # 等待服务稳定
                
                if "逐步扩大流量" in step.step_name:
                    # 模拟逐步扩大流量
                    for percentage in [10, 25, 50, 75, 100]:
                        logger.info(f"流量比例: {percentage}%")
                        await asyncio.sleep(3)
            
            logger.info(f"金丝雀发布完成: {self.release.version}")
            return {"success": True, "strategy": "canary"}
            
        except Exception as e:
            logger.error(f"金丝雀发布失败: {e}")
            return {"success": False, "error": str(e)}


class RollingDeployment(BaseDeploymentStrategy):
    """滚动更新策略"""
    
    async def deploy(self) -> Dict[str, Any]:
        """执行滚动更新"""
        try:
            logger.info(f"开始滚动更新: {self.release.version}")
            
            # 获取部署步骤
            steps = self.db.query(ReleaseStep).filter(
                ReleaseStep.release_id == self.release.id
            ).order_by(ReleaseStep.step_order).all()
            
            for step in steps:
                success = await self.execute_step(step)
                if not success:
                    return {
                        "success": False,
                        "error": f"步骤 {step.step_name} 执行失败",
                        "step": step.step_name
                    }
                
                # 滚动更新需要逐步替换实例
                if "逐步更新实例" in step.step_name:
                    # 模拟逐步更新实例
                    for i in range(3):  # 假设有3个实例
                        logger.info(f"更新实例 {i+1}/3")
                        await asyncio.sleep(2)
            
            logger.info(f"滚动更新完成: {self.release.version}")
            return {"success": True, "strategy": "rolling"}
            
        except Exception as e:
            logger.error(f"滚动更新失败: {e}")
            return {"success": False, "error": str(e)}


class RecreateDeployment(BaseDeploymentStrategy):
    """重新创建策略"""
    
    async def deploy(self) -> Dict[str, Any]:
        """执行重新创建部署"""
        try:
            logger.info(f"开始重新创建部署: {self.release.version}")
            
            # 获取部署步骤
            steps = self.db.query(ReleaseStep).filter(
                ReleaseStep.release_id == self.release.id
            ).order_by(ReleaseStep.step_order).all()
            
            for step in steps:
                success = await self.execute_step(step)
                if not success:
                    return {
                        "success": False,
                        "error": f"步骤 {step.step_name} 执行失败",
                        "step": step.step_name
                    }
            
            logger.info(f"重新创建部署完成: {self.release.version}")
            return {"success": True, "strategy": "recreate"}
            
        except Exception as e:
            logger.error(f"重新创建部署失败: {e}")
            return {"success": False, "error": str(e)}


def get_deployment_strategy(release: Release, db) -> BaseDeploymentStrategy:
    """获取部署策略实例"""
    strategy_map = {
        "blue_green": BlueGreenDeployment,
        "canary": CanaryDeployment,
        "rolling": RollingDeployment,
        "recreate": RecreateDeployment
    }
    
    strategy_class = strategy_map.get(release.strategy)
    if not strategy_class:
        raise ValueError(f"不支持的部署策略: {release.strategy}")
    
    return strategy_class(release, db)
